1. Field of the Invention
This invention relates to ink agitators used to prevent the setting of ink in printing press fountains, and more particularly to an ink agitator for very stiff inks such as those dried by ultraviolet light. Unfortunately, such inks also setup very readily; ambient light, such as that from florescent lamps, speeds up the setting process.
2. Prior Art Information
Printing presses today employ rotatable cones whose pointed ends extend into the ink fountains. A cone is mounted on a mechanical arm which moves a distance across a fountain sufficient for the cone to stir the ink therein. However, the mechanism is ineffective to keep the quicksetting stiff inks at a pliable viscosity.
Ink agitator patents include U.S. Pat. Nos. 584,247 (Templin); 1,615,769 (Ortleb et al); 1,077,882 (Holz); 1,401,218 (Weldon); 1,778,600 (Jones); 1,835,325 (Ortleb); and 2,447,868 (Ortleb). Templin moves agitator blades D back and forth across an ink fountain. Holz rotates stirrers 12 or 31 down, through, and up the ink in a fountain to move the ink against an ink roller. Weldon moves a stirrer having curved deflection plates 27 back and forth across in ink fountain and in front on a inking roller. Ortleb et al applies short jerky motions to a plurality of fingers 41 travelling back and forth across the spaces between them in an ink fountain. Jones traverses a carriage having a) a scraping blade 35 which moves back and forth through an ink fountain to create a wave which travels from one end of the ink fountain to the other and b) depending wave-braking rods 40 to impart spiral motion to ink portions. Ortleb (U.S. Pat. No. 1,835,325) imparts short jerky strokes to a plurality of stirrers moved relatively slowly back and forth across the spaces between them in an ink fountain. Ortleb (U.S. Pat. No. 2,447,868) moves continuously a plurality of agitating blades 12 back and forth across an ink fountain D.
Modern printing presses use very stiff inks such as those dried by ultraviolet light. Such stiff inks also setup or harden very rapidly, particularly in the presence of florescent ambient light. The identified ink agitators are unsuitable for handling such stiff inks.
Vibrating a printing or dyeing compound to improve penetration of a permeable flat shaped material is taught by Zimmer et al. U.S. Pat. No. 3,902,414. However Zimmer et al do not contemplate using vibration to keep very stiff ink from setting, let alone any inks.